Joseph Pennell in the context of "Thomas Eakins"

Apocalyptic and post-apocalyptic fiction are subgenres of science fiction in which the Earth's (or another place's) civilization is collapsing or has collapsed. The apocalypse event may be climatic, such as runaway climate change; astronomical, an impact event; destructive, nuclear holocaust or resource depletion; medical, a pandemic, whether natural or human-caused; end time, such as the Last Judgment, Second Coming or Ragnarök; or any other scenario in which the outcome is apocalyptic, such as a zombie apocalypse, AI takeover, technological singularity, dysgenics/eugenics, natural disasters, or alien invasions.

The story may involve attempts to prevent an apocalypse event, deal with the impact and consequences of the event itself, or it may be post-apocalyptic, set after the event. The time may be directly after the catastrophe, focusing on the psychology of survivors, the way to keep the human race alive and together as one, or considerably later, often including that the existence of pre-catastrophe civilization has been mythologized. Post-apocalyptic stories often take place in a non-technological future world or a world where only scattered elements of society and technology remain.

A liberty bond or liberty loan was a war bond that was sold in the United States to support the Allied cause in World War I. Subscribing to the bonds became a symbol of patriotic duty in the United States and introduced the idea of financial securities to many citizens for the first time.